scholarly journals Linear-Quadratic Regulator for Control of Multi-Wall Carbon Nanotube/Polydimethylsiloxane Based Conical Dielectric Elastomer Actuators

Actuators ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 18
Author(s):  
Titus Mulembo ◽  
Waweru Njeri ◽  
Gakuji Nagai ◽  
Hirohisa Tamagawa ◽  
Keishi Naito ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Rise Time ◽  
Electromechanical Coupling ◽  
Linear Quadratic Regulator ◽  
Fast Response ◽  
Dielectric Elastomer ◽  
Soft Robotics ◽  
Artificial Muscles ◽  
Linear Quadratic ◽  
Dielectric Elastomer Actuators

Conventional rigid actuators, such as DC servo motors, face challenges in utilizing them in artificial muscles and soft robotics. Dielectric elastomer actuators (DEAs) overcome all these limitations, as they exhibit complex and fast motions, quietness, lightness, and softness. Recently, there has been much focus on studies of the DEAs material’s non-linearity, the non-linear electromechanical coupling, and viscoelastic behavior of VHB and silicone-based conical DEAs having compliant electrodes that are based on graphite powder and carbon grease. However, the mitigation of overshoot that arises from fast response conical DEAs made with solid electrodes has not received much research focus. In this paper, we fabricated a conical configuration of multi-walled carbon nanotube/polydimethylsiloxane (MWCNT/PDMS) based DEAs with a rise time of 10 ms, and 50% peak overshoot. We developed a full feedback state-based linear-quadratic regulator (LQR) having Luenberger observer to mitigate the DEAs overshoot in both the voltage ON and OFF instances. The cone DEA’s model was identified and a stable and well-fitting transfer function with a fit of 94% was obtained. Optimal parameters Q = 70,000, R = 0.1, and Q = 7000, R = 0.01 resulted in the DEA response having a rise time value of 20 ms with zero overshoot, in both simulations and experiments. The LQR approach can be useful for the control of fast response DEAs and this would expand the potential use of the DEAs as artificial muscles in soft robotics.

scholarly journals Soft Robotic Gripper Based on Multi-Layers of Dielectric Elastomer Actuators

2021 ◽  
Vol 33 (4) ◽  
pp. 968-974
Author(s):  
Witchuda Thongking ◽  
Ardi Wiranata ◽  
Ayato Minaminosono ◽  
Zebing Mao ◽  
Shingo Maeda ◽  
...  
Keyword(s):  
Response Time ◽  
Low Cost ◽  
Fast Response ◽  
Dielectric Elastomer ◽  
Heel Strike ◽  
Soft Robotics ◽  
Artificial Muscles ◽  
Light Weight ◽  
Dielectric Elastomer Actuators ◽  
The Relationship

Dielectric elastomer actuators (DEAs) are a promising technology for soft robotics. The use of DEAs has many advantages, including light weight, resilience, and fast response for its applications, such as grippers, artificial muscles, and heel strike generators. Grippers are commonly used as grasping devices. In this study, we focus on DEA applications and propose a technology to expand the applicability of a soft gripper. The advantages of gripper-based DEAs include light weight, fast response, and low cost. We fabricated soft grippers using multiple DEA layers. The grippers successfully held or gripped an object, and we investigated the response time of the grippers and their angle characteristics. We studied the relationship between the number of DEA layers and the performance of our grippers. Our experimental results show that the multi-layered DEAs have the potential to be strong grippers.

scholarly journals Dielectric Elastomer Grippers

2021 ◽  
Vol 10 (5) ◽  
pp. 33-36
Author(s):  
Mills Patel ◽  
Rudrax Khamar ◽  
Akshat Shah ◽  
Tej shah ◽  
Bhavik Soneji
Keyword(s):  
Mechanical Properties ◽  
Power Generation ◽  
State Of The Art ◽  
Artificial Muscle ◽  
Dielectric Elastomer ◽  
Soft Robotics ◽  
Artificial Muscles ◽  
Dielectric Elastomer Actuators ◽  
Working Principle ◽  
Soft Actuators

This paper appraisals state-of-the-art dielectric elastomer actuators (DEAs) and their forthcoming standpoints as soft actuators which have freshly been considered as a crucial power generation module for soft robots. DEs behave as yielding capacitors, expanding in area and attenuation in thickness when a voltage is applied. The paper initiates with the explanation of working principle of dielectric elastomer grippers. Here the operation of DEAs include both physics and mechanical properties with its characteristics, we have describe methods for modelling and its introductory application. In inclusion, the artificial muscle based on DEA concept is also formally presented. This paper also elaborates DEAs popular application such as- Soft Robotics, Robotics grippers and artificial muscles.

Highly flexible and transparent dielectric elastomer actuators using silver nanowire and carbon nanotube hybrid electrodes

Soft Matter ◽  
2017 ◽  
Vol 13 (37) ◽  
pp. 6390-6395 ◽  
Author(s):  
Ye Rim Lee ◽  
Hyungho Kwon ◽  
Do Hoon Lee ◽  
Byung Yang Lee
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Silver Nanowires ◽  
Dielectric Elastomer ◽  
Silver Nanowire ◽  
Dielectric Elastomer Actuator ◽  
Dielectric Elastomer Actuators ◽  
Transparent Dielectric ◽  
Optically Transparent ◽  
Highly Stretchable

Electrodes consisting of silver nanowires and carbon nanotubes enable a dielectric elastomer actuator to become highly stretchable and optically transparent.

scholarly journals Implementation of Soft-Lithography Techniques for Fabrication of Bio-Inspired Multi-Layer Dielectric Elastomer Actuators with Interdigitated Mechanically Compliant Electrodes

Actuators ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 73 ◽  
Author(s):  
Mert Corbaci ◽  
Wayne Walter ◽  
Kathleen Lamkin-Kennard
Keyword(s):  
Soft Lithography ◽  
Skeletal Muscles ◽  
Actuation Voltage ◽  
Transition Process ◽  
Humanoid Robots ◽  
Dielectric Elastomer ◽  
Industrial Robots ◽  
Artificial Muscles ◽  
Dielectric Elastomer Actuators ◽  
Soft Actuators

Advancements in software engineering have enabled the robotics industry to transition from the use of giant industrial robots to more friendly humanoid robots. Soft robotics is one of the key elements needed to advance the transition process by providing a safer way for robots to interact with the environment. Electroactive polymers (EAPs) are one of the best candidate materials for the next generation of soft robotic actuators and artificial muscles. Lightweight dielectric elastomer actuators (DEAs) provide optimal properties such as high elasticity, rapid response rates, mechanical robustness and compliance. However, for DEAs to become widely used as artificial muscles or soft actuators, there are current limitations, such as high actuation voltage requirements, control of actuation direction, and scaling, that need to be addressed. The authors’ approach to overcome the drawbacks of conventional DEAs is inspired by the natural skeletal muscles. Instead of fabricating a large DEA device, smaller sub-units can be fabricated and bundled together to form larger actuators, similar to the way myofibrils form myocytes in skeletal muscles. The current study presents a novel fabrication approach, utilizing soft lithography and other microfabrication techniques, to allow fabrication of multilayer stacked DEA structures, composed of hundreds of micro-sized DEA units.

scholarly journals Dielectric Elastomer Actuator Driven Soft Robotic Structures With Bioinspired Skeletal and Muscular Reinforcement

2020 ◽  
Vol 7 ◽  
Author(s):  
M. Franke ◽  
A. Ehrenhofer ◽  
S. Lahiri ◽  
E.-F. M. Henke ◽  
T. Wallmersperger ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Aerosol Deposition ◽  
Dielectric Elastomer ◽  
Artificial Muscles ◽  
Soft Systems ◽  
Natural Motion ◽  
Dielectric Elastomer Actuators ◽  
Resonance Frequencies ◽  
Wide Range ◽  
Laminate Theory

Natural motion types found in skeletal and muscular systems of vertebrate animals inspire researchers to transfer this ability into engineered motion, which is highly desired in robotic systems. Dielectric elastomer actuators (DEAs) have shown promising capabilities as artificial muscles for driving such structures, as they are soft, lightweight, and can generate large strokes. For maximum performance, dielectric elastomer membranes need to be sufficiently pre-stretched. This fact is challenging, because it is difficult to integrate pre-stretched membranes into entirely soft systems, since the stored strain energy can significantly deform soft elements. Here, we present a soft robotic structure, possessing a bioinspired skeleton integrated into a soft body element, driven by an antagonistic pair of DEA artificial muscles, that enable the robot bending. In its equilibrium state, the setup maintains optimum isotropic pre-stretch. The robot itself has a length of 60 mm and is based on a flexible silicone body, possessing embedded transverse 3D printed struts. These rigid bone-like elements lead to an anisotropic bending stiffness, which only allows bending in one plane while maintaining the DEA's necessary pre-stretch in the other planes. The bones, therefore, define the degrees of freedom and stabilize the system. The DEAs are manufactured by aerosol deposition of a carbon-silicone-composite ink onto a stretchable membrane that is heat cured. Afterwards, the actuators are bonded to the top and bottom of the silicone body. The robotic structure shows large and defined bimorph bending curvature and operates in static as well as dynamic motion. Our experiments describe the influence of membrane pre-stretch and varied stiffness of the silicone body on the static and dynamic bending displacement, resonance frequencies and blocking forces. We also present an analytical model based on the Classical Laminate Theory for the identification of the main influencing parameters. Due to the simple design and processing, our new concept of a bioinspired DEA based robotic structure, with skeletal and muscular reinforcement, offers a wide range of robotic application.

scholarly journals Perancangan Kendali Optimal pada Motor Arus Searah Tanpa Sikat melalui Metode LQRI

2019 ◽  
Vol 7 (2) ◽  
pp. 377 ◽  
Author(s):  
KHOIRUDIN FATHONI ◽  
ARYO BASKORO UTOMO
Keyword(s):  
Rise Time ◽  
Load Condition ◽  
Linear Quadratic Regulator ◽  
Settling Time ◽  
Control Signal ◽  
Bldc Motor ◽  
Linear Quadratic ◽  
Cost Matrix ◽  
R Matrix ◽  
Set Point

ABSTRAKArtikel ini akan menjelaskan perancangan kendali kecepatan MASTS  dengan tujuan diperoleh respon kecepatan MASTS yang tanggap serta memiliki sinyal kendali dan arus minimal. Untuk mencapai hal ini MASTS akan dikendalikan melalui metode Linear Quadratic Regulator (LQR) dengan state yang dipilih adalah arus, kecepatan, dan state integral galat kecepatan. Diperlukan penalaan nilai parameter Q matriks bobot state dan R matriks bobot input untuk mendapatkan performa kecepatan dan arus yang terbaik. Berdasarkan pengujian diperoleh bahwa dengan kendali LQR-I, kecepatan MASTS dapat mengikuti set point dengan respon rise time Tr = 0,03 detik, settling time Ts=0,044 detik, overshoot (OS) 1,6 %, arus Imax=0,16 A dan dutycycle sinyal kontrol umax 56% pada kondisi tanpa beban dan Tr = 0,03 detik, Ts=0,044 detik, OS 1,6 %, Imax=0,16 A dan umax 56% pada kondisi berbeban. Dibandingkan dengan kendali PID ketika tanpa beban mempunyai Tr=0,0176 Ts=0,075 %OS=3,9% umax=96% Imax=0,35 A, LQRI mempunyai respon settling time, sinyal kendali dan arus yang lebih baik.Kata kunci: Motor Arus Searah Tanpa Sikat, Kendali Optimal, Linear  Quadratic Regulator dan Integral ABSTRACTThis paper aimed to discuss further research about BLDC motor speed control so that BLDC not only has fast speed response but also has minimum control signal and current using LQR (Linear Quadratic Regulator) control with chosen states are current, speed of BLDC, and speed error integral state. Tuning of Q and R matrix is required to reach the best speed and current performance. Where Q and R matrix is state cost matrix and input cost matrix, respectively. Result show that LQR-I control can track set point with rise time Tr = 0.03 s, settling time Ts=0,044 s, overshoot (OS) 1,6 %, current Imax=0,16 A and dutycycle control signal umax 56% in no load condition, and Tr = 0,03 s, Ts=0,044 s, OS 1,6 %, Imax=0,16 A dan umax 56% in the load condition. Compared to PID controller which has Tr=0,0176 Ts=0,075 %OS=3,9% umax=96% Imax=0,35 A in no load condition, proposed controller has a better settling time, control signal and current.Keywords: BLDC Motor, Optimal Control, LQR and Integral

scholarly journals Dielectric Elastomer Actuator for Soft Robotics Applications and Challenges

2020 ◽  
Vol 10 (2) ◽  
pp. 640 ◽  
Author(s):  
Jung-Hwan Youn ◽  
Seung Mo Jeong ◽  
Geonwoo Hwang ◽  
Hyunwoo Kim ◽  
Kyujin Hyeon ◽  
...  
Keyword(s):  
State Of The Art ◽  
Dielectric Elastomer ◽  
Artificial Muscles ◽  
Soft Robot ◽  
Optical Components ◽  
Dielectric Characteristics ◽  
Dielectric Elastomer Actuators ◽  
Potential Applications ◽  
Working Principle ◽  
Soft Actuators

This paper reviews state-of-the-art dielectric elastomer actuators (DEAs) and their future perspectives as soft actuators which have recently been considered as a key power generation component for soft robots. This paper begins with the introduction of the working principle of the dielectric elastomer actuators. Because the operation of DEA includes the physics of both mechanical viscoelastic properties and dielectric characteristics, we describe theoretical modeling methods for the DEA before introducing applications. In addition, the design of artificial muscles based on DEA is also introduced. This paper reviews four popular subjects for the application of DEA: soft robot hand, locomotion robots, wearable devices, and tunable optical components. Other potential applications and challenging issues are described in the conclusion.

Comparison of Performance Measures of Speed Control for a DC Motor Using Hybrid Intelligent Controller and Optimal LQR

2014 ◽  
Vol 622 ◽  
pp. 23-31
Author(s):  
T. Velayudham Narmadha ◽  
Chackaravarthy Baskaran ◽  
K. Sivakumar
Keyword(s):  
Rise Time ◽  
Linear Quadratic Regulator ◽  
Speed Control ◽  
Dc Motor ◽  
Pid Controllers ◽  
Rule Base ◽  
Fuzzy Pid ◽  
Linear Quadratic ◽  
Lqr Controller ◽  
Fuzzy Pd

-In this paper , performance of fuzzy PD , fuzzy PI , fuzzy PD+I , fuzzy PID controllers are evaluated and compared. This paper also describes the speed control based on Linear Quadratic Regulator (LQR) technique. The comparison is based on their ability of controlling the speed of DC motor, which merely focuses on performance index of the controllers, and also time domain specifications such as rise time, settling time and peak overshoot. The controller is modelled using MATLAB software, the simulation results shows that the fuzzy PID controllers are the best performing candidates in all aspects but it as higher overshoot and IAE in comparison with optimal LQR. The Fuzzy PI controller exhibited null offset but suffers from poor stability and peak overshoot, whereas the fuzzy PD controller has fast rise time, with no overshoots but the IAE is much greater. Thus, the comparative analysis recommends fuzzy PID controller but it is usually associated with complicated rule base and tedious tuning. To circumvent these problems, the proposed LQR controller gives better performance than the other controllers.

Dynamic Modeling and Experimental Validation of an Annular Dielectric Elastomer Actuator With a Biasing Mass

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Gianluca Rizzello ◽  
Micah Hodgins ◽  
David Naso ◽  
Alexander York ◽  
Stefan Seelecke
Keyword(s):  
Electromechanical Coupling ◽  
Dielectric Elastomer ◽  
Reference Case ◽  
Dielectric Elastomer Actuators ◽  
Annular Geometry ◽  
Standard Linear ◽  
Dynamic Loading Conditions ◽  
Actuator Design ◽  
Static And Dynamic Loading ◽  
Relevant Range

This paper presents a model for the electromechanically coupled dynamic behavior of dielectric elastomer actuators (DEA). The main goal is to develop a lumped, dynamic model which can be used for the optimization of actuator design in specific applications as well as for the synthesis of high precision, model-based feedback control algorithms. A mass-biased membrane actuator with an annular geometry is chosen as a reference case to introduce the modeling concept. The mechanical model extends standard linear visco-elasticity through the introduction of a nonlinear hyperelastic Ogden element. Electromechanical coupling is implemented through the Maxwell stress concept. The DEA model is then experimentally calibrated and validated for both quasi static and dynamic loading conditions. It can be shown that both mechanical preloading and electric actuation can be reproduced over a relevant range of masses and frequencies.

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